There's a lot of assumptions going on here. Domesticated pigs can live up to 23 years. We'd also need to know if heart failure is a leading cause of death in pigs, if it's not then the heart could be viable long past that age. There are a lot of completely unknown factors like how a xenotransplant will fare in the host body over a long period of time. That's open ended if there are no rejection issues due to gene editing. Also, the person in the article clearly doesn't share your view on death and there are a large number of people out there that agree with him. Their chance at a longer life shouldn't be curtailed by other people's preconceptions.